Flat tire safety roller and warning indicator

ABSTRACT

1. A SAFETY INSERT FOR INFLATABLE TIRES OF THE TUBELESS TYPE WHEREIN BEADS AT THE INNER OPEN PERIPHERY OF THE TIRE ARE ADAPTED TO SEALABLY ENGAGE SIDE FLANGES OF A MOUNTING RIM AND SAID RIM INTERMEDIATE THE FLANGES HAS A DROP-CENTER OF REDUCED DIAMETER FACILITATING ATTACHMENT AND DETACHMENT OF THE TIRE, SAID SAFETY DEVICE COMPRISING A PLURALITY OF SIMILAR ARCUATE MEMBERS, EACH OF SAID ARCUATE MEMBERS HAVING AT EACH END ESSENTIALLY CIRCULAR COUPLING PORTIONS OF REDUCED THICKNESS IN THE PLANE OF SAID MEMBERS TO INTERFIT WITH COUPLING PORTIONS ON ADJACENT MEMBERS, SAID CIRCULAR PORTIONS HAVING AT THE CENTERS THEREOF COACTING COUPLING MEANS PROVIDING, WHEN LOOSELY COUPLED, WIDE COPLANAR PIVOTAL MOVEMENT OF ADJACENT ARCUATE MEMBERS, WHEREBY AFTER PARTIAL ASSEMBLAGE WITHIN A TIRE, AND THEN MOUNTING ONE TIRE BEAD ON A RIM, THE SUBASSEMBLAGE CAN BE PASSED OVER THE RIM AND INTO THE DROP-CENTER THEREOF FOR FINAL ASSEMBLAGE ABOUT THE RIM BY COUPLING A SINGLE JOINT, AND SAID COUPLING MEANS PROVIDING FIRM CLAMPING OF INTERFITTING COUPLING PORTIONS OF SAID PLURALITY OF ARCUATE MEMBERS TO FORM A RING MEMBER HAVING AN INNER PERIPHERY SEATING IN THE DROP-CENTER OF SAID RIM AND AN OUTER PERIPHERY PROTRUDING BEYOND THE FLANGES OF SAID RIM, SAID INNER AND OUTER PERIPHERIES OF THE RING BEING FORMED OF RIGID PLASTIC MATERIAL HAVING LUBRICANT QUALITIES, AND MEANS JOINING SAID INNER AND OUTER PERIPHERIES IN A LIGHTWEIGHT STRUCTURE PROVIDING A RADIAL COMPRESSIVE STRENGTH APPROPRIATE TO WITHSTAND THE LOADS FOR WHICH THE PARTICULAR TIRE IS INTENDED.

Oat. 15, 1914 T. c. PATECELL FLAT TIRE SAFETY ROLLER AND WARNINGINDICATOR 2 Sheets-Sheet 1 Original Filed Oct. 9, 1969 INVENTO R M50002:a P4 7504-; 4

BY %MJ 8 /av Ll ATTO R N EY 0d. 15, 1914 -r. c. PATECELL FLAT TIRESAFETY ROLLER AND WARNING INDICATOR Original Filed 001. 9. 1969 2Sheets-Sheet 2 FIG. IO

INVENTOR THEODQAECPflTECEZL ATTORNEY 28,196 FLAT TIRE SAFETY ROLLER ANDWARNING INDICATOR Theodore C. Patecell, 33-52 156th St., Flushing, N.Y.11354 Original No. 3,635,273, dated Jan. 18, 1972, Ser. No. 865,122,Oct. 9, 1969. Application for reissue Jan. 10, 1973, Ser. No. 322,425

Int. Cl. 1360c 17/04 US. Cl. 152-158 51 Claims Matter enclosed in heavybrackets appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE A safety insert or roller for inflatabletires comprising a plurality of arcuate members having detachable andpivotal clamping engagement adapted to form a ring closely engaging thedrop center of a tire mounting rim and protruding beyond said rim asubstantial distance in the direction of the tread of an inflated tiremounted thereon. At least the inner and outer peripheries of theassembled ring are of rigid plastic material, preferably havinglubricant properties, such for example as high density polyethylene.Connecting structure between said inner and outer peripheries can be ofthe same material or a different material such as formed metal, and isfashioned to provide a combination of low weight and high tensile andcompression strength. Overlapped end portions of the arcuate memberswhen loosely joined together permit relative swinging movementfacilitating assembling the device within a tire while half mounted on arim; and the fastening means for adjacent ends of the arcuate membersincluding bevelled means for providing circumferential clamping of theassembled ring in the tightening thereof.

This is an application for re-issue of my prior US. Pat. No. 3,635,273which issued Jan. 18, 1972.

BACKGROUND OF THE INVENTION The problem of increasing the safety ofinflatable tires, and particularly the relatively large low pressuretires intended for high speed automotive use, has long presented achallenge, particularly with tubeless tires in which air pressure ismaintained by the engagement between beads at the inner tire peripheryand flanges on a rim or the rim portion of a wheel. The loss of airpresents a plurality of difliculties for the motorist. Sudden loss ofair, as in the case of a blowout at high speed or even at moderatespeed, frequently results in loss of control leading to seriousaccidents. Furthermore, when a tire is deflated, it is impossible tocontinue to move the vehicle without serious damage to the tire andpossible damage to the vehicle. This creates a secondary problem whentire trouble is encountered on congested highways, causing traflictie-ups and jeopardizing the safety of the vehicles occupants and anyoneattempting to replace or repair the tire.

Because it is impossible to drive on a deflated tire, it is essentialthat all vehicles carry an inflated spare tire together with equipmentfor quickly making a change in the event of tire trouble. This addsappreciable weight and bulk to the storage facilities of a vehiclewhich, in many instances, particularly when tires are properly caredfor, may constitute, in etfect, excess baggage.

Various attempts have been made in the past to provide insert meanswithin an inflatable tire which might minimize the danger of loss ofcontrol in the event of United States Patent sudden loss of air at highspeed and which would permit driving for reasonable distances on adeflated tire. Such approaches have included secondary inflatable unitswhich will expand when the main tire pressure is released, the use ofinserts fashioned from rubber or other resilient material of suflicientbulk to carry the load if air pressure is lost, fillers of granularsolid material an various types of rigid inserts attached to orassociated with the mounting rim providing, in effect, a supplementalwheel projecting beyond the rim edge in the direction of the tread of aninflated tire.

The inflatable insert has the disadvantage that an occurrence whichleads to loss of air in the tire itself may also rupture the inflatableinsert, rendering it useless. The resilient type of solid insert, whichinherently bears against portions of the inflated tire, is objectionabledue to the friction and heat generated as a result of the normal flexingof the tire sidewalls in use; and in high speed travel, anything thatcauses an increased generation of heat within a tire is inherentlyobjectionable.

Fillers which have been tried include particles of plastic foam, rubberfoam and various chemicals. These tend to cause problems due to heatgeneration because of flexing of a tire when in use. Furthermore, suchmaterials in shifting about can cause changes in weight distribution anddangerous unbalanced conditions. Also extended parking can so compressthe filler as to cause a flat spot which will at least temporarily alterthe riding qualities of the tire, and tends to increase the possibilityof the weight shifting above mentioned.

In principle, a rigid insert associated with the tire rim would appearto be the most practical approach to a reliable safety device; andnumerous attempts, as evidenced by issued patents, have been made toprovide an eflectice safety device of this type. These have beengenerally impractical, however, for various reasons. Some have involvedfixed mounting to the rim, which is inherently expensive and complicatesthe problem of mounting a tire over the assemblage. Others have involvedthe use of specially constructed rims or rimmed wheels. Typical ofpatents showing such devices are US. patents to W. L. Lindley No.2,986,189 dated May 30, 1961, No. 3,142,- 326 dated July 28, 1964, andNo. 3,180,391 dated Apr. 27, 1965. A further patent to Lindley, No.3,237,667 dated Mar. 1, 1966, comes somewhat closer to providing apractical solution in the sense that it involves a plurality of arcuatemembers which can be clamped to a tire rim without modification of therim. This patent, however, provides at the outer periphery of the insertmembers, a surface of tansverse rubber teeth or serrations which areintended to contact the inner surface of a tire when deflated and passthe tire through the point of contact with the roadway on rotationwithout damage." While such a structure might function satisfactorilyfor a very brief interval, such as the time involved to stop a vehiclein the event of a blowout, any extended riding on the deflated tirewould ra idly generate so much heat as to destroy the facing of theinsert and/or the tire itself.

The device of Lindley Pat. No. 3,237,667 is also considered to bestructurally unsound since it would be incapable of withstanding theside loads which would be encountered, particularly in steering, whenriding on a flat tire. Furthermore, the cost of producing the Lindleydevice, which cannot be die cast or molded, would be prohibitive.

Thus, in spite of rather extensive prior eflorts, it appears that no oneheretofore has been able to provide a safety insert for inflatable tireswhich can be economically produced and easily installed, and which atthe same time will permit driving for substantial distances with adeflated tire without significant damage to the tire insert.

3 THE INVENTION It has now been discovered in accordance with thepresent invention that it is possible to provide a safety tire insertcomprising a plurality of arcuate members which, as assembled within atire, will firmly grasp the tire rim, and which by reason of the natureof the material employed at the inner and outer peripheries thereof,can, when contacted by the inner surface of a deflated tire, permitsslippage between the insert and the inner surface of the tire and/orbetween the insert and the tire rim which prevents a buildup of heat,and permits riding for substantial distances on a deflated tire withoutdamage to the tire or insert. In order to provide this slippage, theinner and outer peripheries of the insert member should be essentiallysmooth and fashioned from rigid plastic material having appropriatestrength for the intended loads, and having by reason of the chemicalnature of such plastic material lubricant qualities with respect to theengaged surfaces of the tire and tire rim. It is found, for example,that certain plastic materials such as high density polyethylene andpolypropylene, which can provide the desired structural strength, alsoprovide the type of lubricant effect needed in the engagement with theinner surfaces of the tire and tire rim. It is to be understood,however, that various other plastic materials of either thethermoplastic or thermosetting types can be employed.

The insert unit of the present invention comprises a plurality ofarcuate members which can be quickly and easily assembled to a rim whichis half inserted within a tire; i.e., one tire bead inside the rim andone outside the rim. For simplicity in production and handling, it ispreferably to employ two similar arcuate members having fastening meansassociated therewith which permit joining such members as a completering clamped to the tire rim without the use of any special tools orimplements.

In a device of this sort, it is essential to provide com pressivestrength to withstand the loads generated by a fast-moving vehicle witha tire deflated as well as tensile strength and rigidity to withstandthe centrifugal forces of extended high speed travel with the tireinflated. At the same time, it is important to maintain the overallweight of the insert as low as possible. These objectives can berealized by two basically different approaches. The arcuate membersmaking up the insert can be wholly fashioned from the particular plasticmaterial employed in the inner and outer peripheries thereof with thethickness of the unitary members suitably reduced at points between saidinner and outer peripheries to provide an optimum balance of weight vs.compressive and tensile strength. Alternatively, the connecting meansbetween the inner and outer peripheries of the insert can be arcuatemembers fashioned from metal or plastic material different from thatemployed at the peripheries of the insert. Here again, the structure andthickness of the connecting means in various radial and circumferentialportions thereof will be substantially varied to provide the desiredbalance of weight vs. compressive and tensile strength.

Improved safety inserts for inflatable tires having the characterizingfeatures above mentioned have been subjected to extensive road testingand found to perform in a highly effective manner. Under normal drivingconditions, even at speeds of the order of 70-8O mph, the presence ofthe inserts within the tires does not affect the performance or comfortof the vehicle. In the event of blowout, even at high speed, the vehicleremains manageable and the tire is prevented from being thrown from therim and does not incur significant damage beyond the initial damage ofthe blowout. In the event of a slow leak, the driver will become awareof the fact when the loss of air permits the inner surface of the tireto contact the insert unit due to a noticeably harder ride, but he cancontinue driving for considerable distances with a partially orcompletely deflated tire without discomfort and without any appreciabledamage to the tire. It is possible, for example, with a deliberatelydeflated tire, to continue driving at speeds up to about 20-25 mph. foras much as 8-10 miles, pull into a service station and refill the tirewith air, and then drive on as if nothing has happened. Higher speedsare safe and possible, with good controllability of the vehicle, but theincreased heat generated may damage the tire.

The ability to thus drive substantial distances on a dafiated tire withcomplete safety and control is due to the limited tire deformation whichpermits it to remain balanced on the rim or wheel. With the insert inplace, the tire beads cannot slide into the drop-center, and the spacingof the outer surface of the insert from the rim edge prevents thesidewalls from completely collapsing, which in turn tends to keep thetire tread in proper alignment. The result is that substantial tractionand braking capacity is maintained even with a completely deflated tire.

The practical advantages of this type of performance to the motorist andto the public in general are considered to be quite substantial,particularly when viewed in terms of congested and high speed parkwaytravel. By being able to move on at a reasonable speed with a deflatedtire, the driver can proceed to an appropriate turnoff point for thenext service station for tire change or repair, thereby avoiding therisks to himself and his passengers which would be inherent in stopping,and at the same time, eliminating the traflic tie-up which might resultif he did stop. Furthermore, by being able to drive at least 8 to 10miles on a daflated tire without appreci able damage to the tire (andsubstantially greater distances if one were not concerned about damageto the tire), much automotive travel would be conducted in areas havingservice stations so frequently spaced that there would be no need forcarrying a spare tire or a jack and other tools required to change atire on the road. Elimination of these items would obvious enhance theeffective use of space within the vehicle.

When a tire equipped with the insert is properly inflated, the innersurface of the tire will rarely contact the insert. 0n the other hand,when a tire is about 25% deflated, i.e., when a proper pressure of 28p.s.i. has dropped to about 21 p.s.i., there will be a noticeable thumpwhen passing over holes or abnormal joints or extrusions in the road;and when the tire is about 50% deflated the motorist will feel a slightvibration in the car as he passes over small ripples in the road. Thus,the insert provides a practical warning indicator to the motoristconcerning improper tire pressure and/or slow leaks.

Novel features of the improved safety device in accordance with thepresent invention will be more readily understood from a considerationof the following descrip tion taken together with the accompanyingdrawing, in which certain preferred adaptations are illustrated with thevarious parts thereof identified by suitable reference characters ineach of the views, and in which:

FIG. 1 is a plan view of one form of assembled safety device showingfragmentary association with a tire and FIG. 2 is a sectional viewsubstantially on the line 2-2 of FIG. 1.

FIG. 3 is a sectional view substantially on the broken line 33 of FIG.1.

FIG. 4 is a view partially in section substantially on the line 4-4 ofFIG. 1.

FIG. 5 is a plan view showing the device of FIG. 1 partially extendedand illustrating the relative position assumed in the operation ofapplying the same to a tire mm.

FIG. 6 is a plan view of a modified form of insert unit.

FIG. 7 is a composite view of the device shown in FIG. 6 in a positionof partial assemblage.

FIG. 8 is a sectional view substantially on the line 88 of FIG. 6.

FIG. 9 is a sectional view substantially on the line 9-9 of FIG. 6; and

FIG. 10 is a fragmentary view in the direction of the arrows 6-6 of FIG.7.

The drawing illustrates two basic modifications of the improved safetyinsert, FIGS. l-5 relating primarily to an insert in which the inner andouter peripheries are formed integrally with the connecting meanstherebetween, and FIGS. 6-10, relating to a structure in which inner andouter peripheral bands are secured to arcuate connecting means.

As shown in FIGS. l-S, the safety insert comprises a pair of similararcuate members 11, 11', each having male coupling ends 12, 12' andfemale coupling ends 13, 13'. The coupling ends 12, 13 and 12', 13' areat opposite sides of a transverse center line of the arcuate members 11,11' as clearly shown in FIGS. 4 and 5 to provide enlarged bearingsurfaces of generally circular contour which overlap at the center lineas clearly shown at 14, 14' in FIG. 4. Centrally of each bearing surface14' is an aperture 15 registering with a threaded nut or socket 16'which is fixedly secured to the coupling end 13'. The nut or socket 16'can be embedded within the material of the coupling end 13' or can besecured thereto by suitable rivets or fasteners as indicated at 17.

The aperture 15' and the threaded nut or socket 16 receive the end of athreaded bolt 18 extending through the male coupling part 12 and havingan appropriate Wing head or fingerpiece 19 engaging the outer surface ofthe coupling end 12. The portion of the bolt 18 passing through thecoupling end 12 is provided with a bevelled enlargement 20 having alarger diameter adjacent the outer surface of the coupling end 12 and asmaller diameter adjacent the inner surface thereof and adapted to seatin a correspondingly tapered aperture 21 extending through the couplingend 12. The bolt assemblage including the shank 18, fingerpiece 19, andbevelled portion 20, can be completely detachable from the coupling end12, but is preferably loosely coupled therewith by suitable restrainingmeans, as will be hereinafter described When discussing FIG. 9 of thedrawing.

The inner diameter of the aperture 21 is somewhat larger than thediameter of the aperture 15' as will be clearly seen in FIG. 4 of thedrawing, permitting the parts to be initially assembled in partialnon-alignment and brought into alignment by the action of the taperedportion 20 of the bolt moving transversely of the surface 21 as the boltis tightened. It will be apparent that this relative movement has theeffect of reducing the circumferential dimension of the assemblage asthe coupling ends are clamped together. As thus clamped together, itwill be noted that the rounded end surface of the respective clampingends fit within closely conforming cutout contours 22, 22 of theopposing arcuate member. These rounded contours have the same center ofcurvature as the axis of the bolt 18, whereby during loose associationof one pair of coupling ends as seen in FIG. 5, the parts will havesubstantial swinging movement about the bolt 18. The inner peripheries23, 23' of the arcuate members are intended, when the members are fullyclamped together, to have a close peripheral and clamping engagementwith the drop-center 24 of a tire rim 25 having outwardly extending sideflanges 26 as seen in FIG. 2 for sealably engaging inner edges or beads27 of an inflatable tire 28. The outer peripheries 29, 29' of thearcuate members provide in the fully assembled device a circular surfaceconcentric with the inner peripheries 23, 23 and protruding outwardlyfrom the rim flanges 26 a distance of the order of 3060% of theprotruding distance of the inner surface 28a of an inflated tire tread.

As shown in the drawing, the inner and outer peripheries of the arcuatemembers 11, 11 are of substantial width. This width is generally of theorder of 1 /2" to 1%" for the average tire of moderate size, but can belarger or smaller in adapting the device for use with tires and rims ofditferent size and type. With tires of the socalled wide oval type, itmay 'be desirable, as more fully hereinafter described in connectionwith FIGS. 6-9, to provide extra width in the outer periphery of thesafety insert. It will also be understood that in certain instancesspecial shape or contour in a particular drop-center 24 of a rim orwheel may require corresponding shaping of the inner peripheral contourof the safety insert. In the majority of instances, however, there willbe sufficient width in the drop-center 24 to permit the proper seatingof an insert unit having an inner periphery of cylindrical curvature asshown in the drawing.

It is preferable to provide a plurality of spaced lugs as indicated at11a on one side of the arcuate members 11, 11' to rather snugly fit thedrop-center 24 and thereby maintain the insert in proper alignment onthe wheel or rim 25. The lugs 11a, if present, should be on the sameside of the insert unit as the fingerpieces 19 to aid in mounting ashereinafter described.

The arcuate members 11, 11' of the device as shown in FIGS. 1-5constitute cast or molded bodies providing integral connecting meansbetween the inner peripheries 23, 23' and the outer peripheries 29, 29'.Each of the arcuate members is provided with a plurality of largerecesses 30, 30 on opposed surfaces thereof having a depth less thanhalf the thickness of the insert members to leave web portions 31, 31'.Other smaller recesses 32, 32' adjacent the inner and outer peripheriesand between the recesses 30, 31 also extend to a depth less than halfthe thickness of the arcuate members 11, 11' to leave web portions 33,33'. l

The web portions 31, 31' and 33, 33, while generally of the order of A"in thickness, can be varied substantially with different size devicesand with different physical properties such as tensile and compressivestrength in the material of construction. The function of the recessesis to reduce as much as possible the weight of the assemblage withoutsacrificing essential compressive and tensile strength. Furthermore, theemployment of recesses leaving web portions as above describedfacilitates molding, providing improved flow of material within moldcavities as compared with a device having apertures extending completelythrough the structure. It should be understood, however, that effectivecombinations of weight and strength can also be achieved in structureswherein the web portions 31, 31' and 33, 33 are omitted so thatapertures extend completely through the device. Furthermore, the numberand arrangement of the recesses is merely illustrative and can besubstantially varied. It is desirable, however, that any arrangement ofrecesses or apertures should be selected with a view to maintainingbalance in the assembled insert to thereby avoid vibration in the highspeed rotation of a rim or wheel on which the device is mounted.

In assembling the device on a wheel or rim, a tire is first half mountedon the rim; i.e., one bead within the rim and one bead outside the rim.With most wheel or rim constructions, the bead of the outer tire wallshould be first mounted on the rim. The separate arcuate members 11, 11aare then placed within the tire but outside the rim and one pair ofcoupling ends 12, 13 are loosely joined together as shown in FIG. 5. Thefree coupling ends 12', 13 are then inserted in the drop-center 24 ofthe rim 25 and the loosely joined coupled ends 12, 13' are forcedupwardly as seen in FIG. 5 to pass over the rim edge or flange 26. Inthis position, the previously inserted ends 12', 13 and portions of theouter peripheries of the arcuate members 11, 11' will bear against theinner surface 28a of the tire, tending to restrict movement over the rimedge as above described, and to facilitate this mounting step it isdesirable on the coupling ends 12, 13' and 12, 13 to provide smallarcuate cutouts 34 generally conforming to the curvatures of thedrop-center and edge of the rim 25. When the joined ends of the arcuatemembers 11, 11 are within the frame, they are brought into engagementwith the drop-center 34, the free ends 12',

13 are brought together and loosely joined by means of the bolt orfastener 18.

The assemblage is then properly oriented with respect to the dropcenter24 and both fastening elements are tightened by rotation of the wingheads or fingerpieces 19, which are disposed in the direction of theinner wall of the tire. The inner tire bead is then inserted within therim in the conventional manner and the assemblage is ready for inflationof the tire. As is customary with tubeless tires. the internal airpressure acts to properly seat the tire beads 27 against inner surfacesof the rim flanges 26 to thereby seal air within the tire. It will benoted that orientation of the lugs 11a on the same side of the insertunit as the fingerpieces 19 provides some room for movement of the innertire bead into the drop-center to facilitate the insertion of this beadwithin the rim flange 26.

As shown in the drawing, the assembled unit within a tire, with theinner peripheries 23, 23 in clamping engagement with the rim drop-center24 protrude outwardly from the rim edge so that the outer peripheries29, 29' are located essentially midway between the rim edge and theinner surface 28a of the inflated tire. The extent of this projection asshown in FIG. 2 is approximately 45% f the distance to the inner surface28 of the tire, but this distance can be varied substantially Within therange of about 30-60% of the distance from the rim edge to the tiresurface.

When the arcuate members 11, 11' of the device as shown in FIGS. 1-5 arefashioned from high density polyethylene or polypropylene, the inherentlubricant qualities of such materials permit relative sliding movementbetween the inner peripheries 23, 23' and the drop'center 24 and betweenthe outer peripheries 29, 29 and the inner tire surface 28a when lack ofair within the tire permits the road pressure to flatten or deflect thetire tread 28 so that the inner surface thereof engages the insert asshown in FIG. 2. To the extent that the circumference of the inflatedtire differs from the circumference of the outer periphery 29, 29' ofthe insert, it is necessary to provide this amount of relative slippagein each revolution of the tire while riding on the tire in a deflatedcondition. Thus, the lubricant characteristics are of primary importancein minimizing the generation of heat and associated damage to either theinsert or the tire.

It appears that once a tire is sufliciently deflated to be in constantcontact with the insert the slippage will take place primarily betweenthe drop-center of the wheel and the closely conforming inner peripheryof the insert. In other words, when riding on a fully deflated tire thespeed of movement of the contacting portions of the tire and outersurface of the insert will be substantially the same, but the innersurface of the insert will be sliding with respect to the surface of thedrop-center of the rim as the insert rotates, bearing fashion, about therim.

The compressive and tensile strength of the moldable material such ashigh density polyethylene and polypropylene can be substantiallyincreased by incorporating inorganic filler materials including, inparticular, fibrous fillers such as glass fiber filaments. The amount ofsuch tiller can be of the order of 2530% by weight of the moldingcomposition.

Turning now to the modification shown in FIGS. 6-9 of the drawing,arcuate members 35, 35' are made up of arcuate cores or spacers 36, 36'having inner peripheral bands 37, 37' and outer peripheral bands 38, 38'firmly bonded thereto. As clearly shown in FIG. 8 of the drawing, thecores or spacers 36, 36 are of generally I-beam cross-sectional formhaving inner peripheral flanges 39, 39', outer peripheral flanges 40,40', and perpendicularly disposed connecting webs 41, 41'. At regularlyspaced intervals are radially disposed stiffening members 42, 42'integrally joining the inner and outer peripheral flanges and webs toform a rigid lightweight structure. The wall thicknesses of theseflanges and webs can vary considerably, depending upon rim and tire sizeand expected loads for which the device is intended, as well as thematerial of construction and its compressive and tensile strength. Whenworking with parts formed of cast or molded aluminum and with averageautomotive tires, these wall thicknesses will be suitably of the orderof A", although the thickness of the inner flange and connecting web maysuitably be less than the thickness of the outer flange.

The peripheral bands 37, 37' and 38, 38' are secured to the flanges 39,39' and 40, respectively by suitable bonding or fastening means, and forpurposes of illustration, the bands have been shown secured to theflanges by flat head bolts 43 recessed in the bands and extendingthrough the flanges to the inwardly disposed nuts 44. The bolts 43 aresuitably spaced at uniform 2" to 3" intervals circumferentially of thebands and intermediate the radial stiffening members 42, 42'.

As with the device shown in FIGS. 1-5, the arcuate members 35, 35' andthe cores 36, 36' thereof are provided with male coupling ends 45, 45'and female coupling ends 46, 46' providing essentially circular bearingsurfaces disposed at opposite sides of the center line of the device asseen in FIGS. 9 and 10 of the drawing. The female coupling ends includecentral apertures 47, 47' terminating in a threaded nut or socket 48,48', which is suitably a lock nut securely anchored in the coupling end.The male coupling parts carry fastening means suitably in the form ofbolts 49, 49' threaded for engagement with the nuts 48, 48 and havingoutwardly extending wings or fingerpieces 5t], 50. Portions of the bolts49. 49' adjacent the fingerpieces 50, 50' have tapered enlargements 51,51' seating within correspoiuiingly tapered apertures 52. 52 in the malecoupling ends 45, 45 which function in the same manner as the structurepreviously described in FIG. 5.

It is desirable that the bolts 49, 49' be supported on the coupling ends45, 45' in general alignment with the tapered apertures 52, 52' to bereadily accessible for manipulation within a tire, when mounting thesafety device. This can be accomplished by various types of resllientstraps or springs, and for purpose of illustration there is shown inFIG. 9 of the drawing an annular groove 53 between the fingerpiece 50and the tapered enlargement 51' receiving a spring ring 54 which, inturn, is secured to the coupling end 45' by suitable fasteners or r vets55. The spring ring 54 permits free rotation and limited axial movementof the bolt 49.

In order to suitably strengthen the coupling ends, it will be noted froma consideration of FIG. 10 that each coupling end, of which 46 isrepresentative, is substantially thicker than the associated Web 41';and the inner peripheries of the coupling ends are defined by arcuateribs 56, 56 extending beyond the webs 41, 41 (note FIGS. 6, 7 and 10).Also having reference to FIGS. 7 and 10, it will be noted that theleading edge 57, 57 of each coupling end curves inwardly and thetrailing edge 58, 58 is undercut to receive the leading edge of anassociated coupling end. This interfitting of the coupling cnds permitslimited pivotal movement of the partly assembled arcuate members 35,35', while maintaining a minimum break or interruption in thecircumferential surface of the bands 38, 38 when the device is fullyassembled as in FIG. 6.

At the inner periphery of the assembled device, it will be noted thatthere is slight spacing between the inner bands and flanges 37, 39 and37', 39 adjacent the coupling ends. This serves to provide the typeclearance helpful in mounting the device on a rim within a tire asdescribed in connection with P16. 5.

The inner and outer peripheral bands 37, 37' and 38, 38' can be the samewidth as the associated flanges 39, 39' and 40, 40. On the other hand,when intended for use in large tires of the so-called wide oval"-type,it is desirable to employ outer bands 38, 38' which are substantiallywider than the associated flanges 40, 40 as seen in FIGS. 8 to 10.

The added width of the bands 38, 38 restrains the large, wide oval,tires from lateral shifting and tends to maintain, when in the flattenedcondition, the symmetrical contour shown in FIG. 2. The bands aresuitably fashioned from plastic or filled plastic materials of the typespreviously described in connection with FIGS. 1 to 5. The outer bands38, 38' can, if desired, be further reinforced by having imbeddedtherein one or more plys of glass fiber strands, fabric woven from glassfiber strands, or similar reinforcing means.

The inner bands 37, 33' can be suitably contoured to conform to theshape of the particular rim drop-center in which it is to be mounted. Inthis connection, it will also be understood that in some instances thebands may include protruding lugs similar to the lugs 11a, previouslydescribed, to properly position the insert unit in a wider drop-center.

The thickness of the bands 37, 37 and 38, 38 can suitably be about Ainch, but can be varied considerably depending on the size of the safetyinsert, the loads for which it is intended, and the strength of theplastic material employed in the bands. As earlier mentioned, lubricantproperties provided by the plastic material at inner and outerperipheries of the insert are of importance in minimizing heat buildupwhen driving on a deflated tire.

Both the primarily plastic safety inserts of FIGS. 1 to 5 and thecombined metal and plastic inserts of FIGS. 6 to 10 have beenextensively tested and formed comparable in performance and ease of use.The structure with the peripheral plastic bands and connecting metalarcuate parts tends to be slightly heavier, but they are moredimensionally stable under conditions of extended high speed driving.When riding on deflated tires, on the other hand, the all plasticdevices appear to be more resistant to deformation and damage due toroughness in the road being traveled. Either type of safety insert orroller is good for the life of the car and interchangeable with othercars having rims or wheels with the same drop-center dimensions. Theinserts weigh approximately one-half as much as average tires for whichthey are intended (and less than one-half as much as heavy duty tires).The cost should be less than that of an average tire, and less thanone-half the cost of premium tires with puncture-proof features. Thus itis considered that there should be a ready market for both types ofdevices with the selection of type being based on driving habits, typeroads normally traveled, and the like.

Various changes and modifications in the safety devices for inflatabletires as herein disclosed will occur to those skilled in the art, and tothe extent that such changes and modifications are embraced by theappended claims, it is to be understood that they constitute part of thepresent invention.

What is claimed is:

1. A safety insert for inflatable tires of the tubeless type whereinheads at the inner open periphery of the tire are adapted to sealablyengage side flanges of a mounting rim and said rim intermediate theflanges has a drop-center of reduced diameter facilitating attachmentand detachment of the tire, said safety device comprising a plurality ofsimilar arcuate members, each of said arcuate members having at each endessentially circular coupling portions of reduced thickness in the planeof said members to interfit with coupling portions on adjacent members,said circular portions having at the centers thereof coacting couplingmeans providing, when loosely coupled, wide coplanar pivotal movement ofadjacent arcuate members, whereby after partial assemblage Within atire, and then mounting one tire head on a rim, the subassemblage can bepassed over the rim and into the drop-center thereof for finalassemblage about the rim by coupling a single joint, and said couplingmeans providing firm clamping of interfitting coupling portions of saidplurality of arcuate members to form a ring member having an innerperiphery seating in the drop-center of said rim and an outer peripheryprotruding beyond the flanges of said rim, said inner and outerperipheries of the ring being formed of rigid plastic material havinglubricant qualities, and means joining said inner and outer peripheriesin a lightweight structure providing a radial compressive strengthappropriate to withstand the loads for which the particular tire isintended.

2. A safety insert for inflatable tires as defined in claim 1 whereinthe means joining said inner and outer peripheries comprises rigidplastic material formed integrally with said inner and outerperipheries.

3. A safety insert for inflatable tires as defined in claim 1 whereinthe means joining said inner and outer peripheries comprises rigidplastic material formed integrally with said inner and outerperipheries, and having varied transverse dimensions and thickness toprovide an optimum balance of high strength and low weight.

4. A safety insert for inflatable tires as defined in claim 3 whereinportions of the means joining said inner and outer peripheries have thesame width or transverse dimension as said peripheries and otherportions may be of reduced dimension of the order of one-eight toone-fourth inch in thickness.

5. A safety insert for inflatable tires as defined in claim 4 whereinsaid portions of reduced dimension are recesses uniformly spacedcircumferentially of said ring to provide balance and minimizecentrifugal strain in the high-speed rotation of the ring.

6. A safety insert for inflatable tires as defined in claim 1 whereinthe means joining said inner and outer periphery of each arcuate membercomprises a separate body portion having inner and outer bands ofconcentric circular contours, an integral connecting web perpendicularto said bands and a plurality of radially disposed stiffening membersprotruding from opposed sides of said web and integrally joined to saidweb and said inner and outer bands.

7. A safety insert for inflatable tires as defined in claim 6 whereinsaid separate body portion is fashioned from metal and the inner andouter bands of said metal body have firmly secured thereto inner andouter bands of said rigid plastic material, said bands of plasticmaterial being at least as wide as the bands of said metal body.

8. A safety insert for inflatable tires as defined in claim 7 whereinthe outer band of plastic material is substantially wider than the outerband of said metal body.

9. A safety insert for inflatable tires as defined in claim 1 whereinthe inner periphery of said ring member is of a width to fit into thedrop-center of said rim, and the outer periphery is at least as wide assaid inner periphery.

10. A safety insert for inflatable tires as defined in claim 9 whereinsaid outer periphery is subtsantially wider than said inner periphery.

11. A safety insert for inflatable tires as defined in claim 1 whereinthe inner periphery of said ring member includes means adapting saidring to engage the full width of said drop-center.

12. A safety insert for inflatable tires as defined in claim 11, whereinsaid last-named means comprises a plurality of circumferentially spacedlugs protruding from said inner periphery at one side of said ringmember.

13. A safety insert for inflatable tires as defined in claim 1 whereineach of said arcuate members has at one end an essentially circularcoupling portion extending to one side of the longitudinal centerline ofsaid member, and at the other end an essentially circular couplingportion extending to the other side of said centerline, said first endcarrying in the center of said circular portion, a female coupling meansand said second end carrying in the center of said circular portion, amale coupling means.

14. A safety insert for inflatable tires as defined in claim 13 whereinsaid male coupling means comprises a bolt having an elongated shank andprotruding actuating head, the portion of said shank adjacent saidactuating head having a frustoconical taper adapted to seat in asimilarly tapered aperture in the associated end of said memher, and theremainder of said shank being of uniform reduced diameter and adapted toengage the female coupling means of a coacting member, saidfrustoconical shank and aperture imparting a circumferential clampingaction when said bold is tightened in assembling a plurality of saidmembers as a complete ring.

15. A safety insert for inflatable tires as defined in claim 13 whereinadjacent members, when loosely joined by engagement of said male andfemale coupling means, are capable of relative pivotal movement aboutsaid coupling means facilitating mounting of said loosely joined memberson a rim within a tire while one bead thereof is disposed within saidrim.

16. A safety insert for inflatable tires as defined in claim 15 whereinsaid circular coupling portions have small portions of reduced radialdimension so positioncd as to reduce the degree of protrusion of saidpivoted members from a rim edge when the free ends thereof are withinthe drop-center of said rim and the pivotably coupled portions are beingpassed over said rim edge.

17. A safety insert for inflatable tires as defined in claim 13. whereinsaid circular coupling portions extend to the outer periphery of saidmembers and overlap at said centerline to provide circumferentialcontinuity in the outer periphery of the assembled ring member.

18. A safety insert for inflatable tires as defined in claim 1 whereinthe radial dimension of said elements is such that when arranged in atire and rim assembly, with the inner periphery closely engaging saiddrop-center of the rim, the outer periphery protrudes beyond the rimedge a distance which is about 30 60 percent of the protrusion of theinflated tire from said rim edge.

19. A safety insert for inflatable tires as defined in claim 1 whereinsaid rigid plastic material is polyethylene.

20. A safety insert for inflatable tires as defined in claim 1 whereinsaid rigid plastic material is high-density polyethylene.

21. A safety insert for inflatable tires as defined in claim 1 whereinsaid rigid plastic material is polypropylene.

22. A safety insert for inflatable tires as defined in claim 1 whereinsaid rigid plastic material contains inorganic filler.

23. A safety insert for inflatable tires as defined in claim 22, saidinorganic filler includes fiberglass filaments.

24. A safety insert for inflatable tires as defined in claim 1 whereinsaid plastic material, at least adjacent the surface of said outerperiphery includes stiffening means.

25. A safety insert for inflatable tires as defined in claim 24 whereinsaid stiffening means comprises fiberglass filaments imbedded in saidplastic material.

26. A safety insert for inflatable tires as defined in claim 24 whereinsaid stiflening means comprises a woven body of fiberglass filamentsimbedded in said plastic material.

27. A safety insert for inflatable tires as defined in claim 24 whereinthe plastic material containing said stiffening means comprises separatebands peripherally secured to said arcuate members.

28. A safety insert for inflatable tires as defined in claim 27 whereinsaid separate bands at the outer periphery of said arcuate members aresubstantially wider than the remainder of said arcuate members.

29. A safety insert for inflatable tires of the tubclcss type whcrcinbonds at the inner open periphery of the tire are adapted to sealablyengage side flanges of a mounting rim, said safety device comprising aplurality of arcuate members, each of said arcuate members having ateach end coupling portions interfitting with coupling portions onadjacent members, means for detachably securing together saidinterfitting coupling portions to thereby assemble said arcuate membersas a ring member having an inner periphery closely and circumferentiallyengaging said rim and an outer periphery protruding beyond the flangesof said rim, means at the inner periphery of all) said ring andcooperating with said rim to maintain said safety insert inpredetermined axial alignment with said rim, whereby the directengagement bctwccn the inner periphery of said ring and said rimfocilitatrs free rotation of said insert about said rim when driving ona dcfiatcd tire, and means joining said inner and outer periphcrics in alightweight structure providing a radial compressive strengthappropriate to withstand the loads for which the particular tire isintended.

30. A safety insert for inflatable tires as dcfincd in claim 29 whereinthe means joining said inner and outer periphcrics comprises rigidplastic matcrlul formed integrally with said inner and outerpcriphurics.

3]. A safety insert for inflatable tires as defined in claim 29 whcrtinthe means joining said inner and outer peripheries comprises rigidplastic material formed intcgrally with said inner and outerperipheries, and having varied transverse dimension and thickness toprovide an optimum buluncc of high strength and low wcight.

32. A safety insert for infltttablc tires as defined in claim 31 wllrrtin portions of the mcans joining said inner and outer peripheries huvethe same width or transverse dimension (1S mid peripheries and otherportions may be of reduced dimension of the order of one-eighth tooncfourth inch in thickness.

33. A safety inscrt for inflatable tires as defined in claim 32 whereinsaid portions of reduced dimension are recesses uniformly spacedcircumfcrentially of said ring to provide balance and minimizecentrifugal strain in the lzigh-spt'cd rotation of the ring.

34. A sufety insert for inflatable tires as defined in claim 29 whcrcinthe mcanr joining suid inner and outcr periphcry of each urcuutc membercomprises a separate body portion having inner and outer bonds ofconcentric circular contours, an integral connecting web perpendicularto said bands and a plurality of radially disposed .rtiflcning membersprotruding from opposed sides of said web and integrally joined to suidweb and said inner and outer bands.

35. A safety insert for inflatable tires as defined in claim 34 whereinsaid separate body portion is fashioned from metal and the inner andouter bands of said metal body have firmly scoured thereto inner andouter bands of said rigid plastic material, said bonds of plasticmutcriul being at least as wide as the bands of .mid metal body.

36. A safety insert for inflatable tires as defined in claim 35 whereinthe outer band of plastic material is substantially wider than the outerband of said metal body.

37. A safety insert for inflatable tires as defined in claim 29 whereinthe inner periphery of said ring member is of a width to fit into adrop-center in said rim, and the outer periphery is at least as wide assaid inner periphery.

38. A safety insert for inflatable tires as defined in claim 37 whereinsaid outer periphery is substantially wider than said inner periphery.

39. A safety insert for inflatable tires as defined in claim 37 whereinthe inner periphery of said ring member includes means adapting saidring to engage the full width of said drop-center.

40. A safety insert for inflatable tires as defined in claim 39, whereinsaid last-namcd means comprises a plurality of circumfercntially spacedlugs protruding from said inner pcriphcry at one side of said ringmember.

41. A safety insert for inflatable tires as defined in claim 29 whereinthe radial dimension of said elements is such that when arranged in atire and rim assembly, with the inner periphery closely engaging saidrim, the outer periphery protrudes beyond the rim edge a distance whichis about 311-60 percent of the protrusion of the inflated tire from saidrim edge.

42. A safety insert for inflatable tires as defined in claim 30 whereinsaid rigid plastic material is polyethylene.

43. A safety insert for inflatable tires as dcfincd in claim 30 whereinsaid rigid plastic material is high-density polyethylene.

44. A safety insert for inflatable tires as defined in claim 30 whereinsaid rigid plastic material is polypropylene.

45. A safety insert for inflatable tires as defined in claim 30 whereinsaid rigid plastic material contains inorganic filler.

46. A safety insert for inflatable tires as defined in claim 45 whereinsaid inorganic filler includes fiberglass filaments.

47. A safety insert for inflatable tires as defined in claim 30 whereinsaid plastic material, at least adjacent the surface of said outerperiphery includes stiffening means.

48. A safety insert for inflatable tires as defined in claim 47 whereinsaid stiflening means comprises fiberglass filaments imbedded in saidplastic material.

49. A safety insert for inflatable tires as defined in claim 47 whereinsaid stiflening means comprises a woven body of fiberglass filamentsimbedded in said plastic material.

50. A safety insert for inflatable tires as defined in claim 47 whereinthe plastic material containing said stifiening means comprises separatebands peripherally secured to said arcuate members.

51. A safety insert for inflatable tires as defined in claim 50 whereinsaid separate bands at the outer periphery of said arcuate members aresubstantially wider than the remainder of said arcuate members.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS M. HENSON WOOD, JR. Primary Examiner 20 D. W.KEEN, Assistant Examiner US. Cl. X.R. 152323; 301--38

